Physics:Quasielastic neutron scattering

From HandWiki

Quasielastic neutron scattering (QENS) designates a limiting case of inelastic neutron scattering, characterized by energy transfers being small compared to the incident energy of the scattered particles. In a more strict meaning, it denotes scattering processes where dynamics in the sample (such as diffusive dynamics) lead to a broadening of the incident neutron spectrum, in contrast to, e.g., the scattering from a diffusionless crystal, where the scattered neutron energy spectrum consists of an elastic line (corresponding to no energy transfer with the sample) and a number of well-separated inelastic lines due to the creation or annihilation of phonons with specific energies. The term quasielastic scattering was originally coined in nuclear physics. It was applied to thermal neutron scattering since the early 1960s, notably in an article by Leon van Hove[1] and in a highly cited one by Pierre Gilles de Gennes.[2]

QENS is typically investigated on high-resolution spectrometers (neutron backscattering, neutron time-of-flight scattering, neutron spin echo).

It is used to investigate topics like

  • solid-state diffusion (e.g. hydrogen in metals)
  • slow modes in crystals (e.g. methyl group rotation)
  • relaxation of viscous liquids

Conference Series

Starting in 1992, there is a conference series entitled QENS. Since 2012, it is being held together with the Workshop on Inelastic Neutron Spectrometry (WINS).

Year Venue Organizing Centre Proceedings Editor
1992 Windsor, UK ISIS ?
1993 San Sebastian, Spain university ?
1995 Parma, Italy university ?
1998 Nyköping, Sweden Studsvik research reactor Physica B 266 (1-2) pp. 1–138
2000 Edinburgh, UK university Physica B 301 (1-2) pp. 1–168 V. Arrighi and M.T.F. Telling
2002 Potsdam/Berlin, Germany Hahn-Meitner-Institut Chemical Physics 292 (2-3) pp. 119–534 R.E.Lechner
2004 Arcachon, France ?
2006 Bloomington, USA Low Energy Neutron Source, Indiana University Cyclotron Facility MRS Conference Series P.E. Sokol et al.
2009 Villigen, Switzerland Paul-Scherrer-Institut Z. Phys. Chem. 224 (1-2) pp. 1–287 R. Hempelmann et al.
2012 Nikkō, Tochigi, Japan J-PARC J. Phys. Soc. Japan 82 Suppl. A (2013) O. Yamamuro et al.
2014 Autrans, France Institut Laue-Langevin EPJ Web of Conferences Vol. 83 (2015) B. Frick, M.M. Koza, M. Boehm, and H. Mutka
2016 Berlin, Germany Helmholtz-Zentrum Berlin M. Russina et al.

Textbooks

  • M. Beé, Quasielastic Neutron Scattering, Adam Hilger: Bristol (1988).
  • R. Hempelmann, Quasielastic Neutron Scattering and Solid State Diffusion, Clarendon Press: Oxford (2000).

References

  1. Van Hove, L.; McVoy, K.W. (1962). "Pair distribution functions and scattering phenomena". Nuclear Physics (Elsevier BV) 33: 468–476. doi:10.1016/0029-5582(62)90539-4. ISSN 0029-5582. https://cds.cern.ch/record/343802. 
  2. de Gennes, P.G. (1963). "Collective motions of hydrogen bonds". Solid State Communications (Elsevier BV) 1 (6): 132–137. doi:10.1016/0038-1098(63)90212-6. ISSN 0038-1098.